Pile screwing apparatus



May 12,'1931. w. A. RAmcE 1,804,706

` PILE SCREWING APPARATUS Filed April 21, 195o 2 sheets-shea 1 May` 12,.1931.

w.'. RADlcE PILE SCREWING APPARATUS Filed April 21, 195o 2 shams-smetr 2atented May 12, i 1931 UNITED STATES .PATENT ori-ucla'. j

l WILLIAM vARCHIIBALD RADICE, OF WESTMINSTER, ENGLAND, ASSIGNOR TBRAITH- WAITE AND COMPANY ENGINEERS LIMITED, OF LONDON, ENGLAND PILEscnnwnve- APPARATUS 1 i Application filed April 21d, i930, serial110.445.9441, and in. Great Britain. June 24,1929.Y

The present invention relates to improvements 1n pile screwlng apparatusparticularly of the type wherein a screw head is detachably engaged invany convenientmanner by a screwing key which transmits the rotation ofthe capstan' or other driving means tothe head.`

o The object of the inventionis to modifyor o adapt pile screwingapparatus of this charactei' so as to render possible the successfulapplication of the yair lift principle of fluid circulation for thepurpose of removing from the bore hole debris ydisplaced by the screwyhead. n

In accordance with the invention the screwing key has a central borewhich'is adapted to constitute the discharge pipe of an air lift system.The air under pressure is ldelivered to an orificed chamber at the lowerend' dentally if the site in which the piles are be-I ing driven in adry one, the scouring fluid supplied in this manner serves to ensure larequisite depthv of water in the bore hole and to maintain the pumpinglevel.

,The accompanying drawings show a 'number of practical applications ofthe invention in the case of a yscrewing head having a central' borewhich is engaged by the hollow screwingkey, Figures 1, `2 and 3j beingvertical sections respectively of the screwing head'and associated partsin illustration of each of three forms of construction. v

Describing firstly those features common to 'allthe constructional formsthe screwing head l` has a through central bore 2 engaged the tubularscrewing key 3 having a central bore 4.` The necessary torque is appliedtionaltorque from thecap'stan or the likev to the screw head is entirelytaken'byl the key 3. The compressedy airfor operating-the.

air lift is supplied conveniently by a flexible hose 7 to a chamber 8with perforated4 walls and situated within the bore 4 in the screwingkey andoclosely adjacent to its lower end. The chamber is convenientlyformed Vby, screwing a perforatedv sleeve 9 into the lower endof thebore so that an annular space is left between the sleeve and theinterior wall of the key. 1

' Detail variations'may be made tosuitcircumstances and three convenientmethods of forming the chamber are illustra-ted.`

In the method illustrated in Figurel the lower end of the screwing keyis internally threaded andthe perforated sleeve 9 has its end portions10 externally screwed -to engage the thread in the bore. Between the4screw threaded portions 10 the wall ofthe sleeve is perforated and thissection indicated by reference 11 isr of smaller diameter than the bore`of the key so that an annular` air chamber is formed around theinteriorof the latter-` The sleeve is screwed into place from the lowerendofthekey. i 'f Q i FigureL 2 illustrates an alternativev arrangementwherein thebore 4 of the screwing key*l itself is increased yindiametery as at l2 over the length covered by the perforated portion ofthe-sleeve,so that thelatter` isof the same diameter throughout and thecontinuity of bore 4 is not materially interrupted'by the air chamberthus formedin its wall. lThe interior of the key is screw threaded'bothabove and belowl the enlargement, 12,r thesleeve which has an upstandingthread 18 at either end being'screwed into place as in theirst example.d f o i The features of the above describedforms of constructionmay becombined as in the arrangement illustrated in Figure 3, wherein the airchamber is formed by decreasing the diameter of the sleeve between itsscrewed end portions, and the internal diameter of the screwing key isin addition increased over the corresponding part of its length.

Wherever the internal bore of the key is increased as in the last twoexamples given' the walls are materially weakened and it is preferabletherefore in such cases to formthe chamber beyond the operativeengagement with the screw head with a view to keeping the weakened partfrom torsional'stress. It will be noted from the drawings that for thisreason the air chamber is situated in that portion of the key projectingbelow the flats 5,. The compressed air pipe 7 which passes through thehollow screwing key is connected to the air chamber 8 by any convenientmeans, and preferably at a point in the wall of the perforated sleeve.

In order to stir up the sediment displaced by the screwing and todisperse it throughout the water so that itmay be readily raised by theairlift, a pipe 14: is provided passing down the hollow screwing key,whereby water under' pressure may be applied to the working face. lThepipe preferably terminates in a jet at a point at or beyond theextremity of thebore in the key. j

It will be seen that the pressure water pipe 14 restricts the bore ofthe screwing key. By' utilizing pipes of various different diameters'therefore the annular space through which the dbris carrying fluid risescan be varied at will to give any desired speed of discharge. The degreeof constriction of the centre portion of sleeve 9 is also a controllingfactor in the speed at which discharge takes place.

Generally speaking t-he pressure water jet and the air lift will beoperated simultaneous- 1y. This would essentially be the case where sandisA traversed during the driving. some, soils however as lfor examplefinclay, itmight be more desirable first to use the water jet for a time,and then to allow the air lift tocome into operation.

What I claim is 1. Pile screwing apparatus comprising inl combination ascrew head, a tubular screwing key engaging the head, an oriced chamberknear the lower end of the bore on the key and means for delivering lairunder pressureV to the chamber.

2. Pilescrewing apparatus comprising in combination a screw. head withal through axial bore an axially bored screwing key elngaging the b'orein the head, a detachable driv-r ing connection between the key and thehead au chamber with' perforated wall within and closely 'adjacent thelower endpof the bore in the key and a 'flexible hose passing throughthe hollow key and communicating with the chamber.

InV

3. Pile screwing apparatus comprising in combination a screw head, witha through axial bore an axially bored screwing key, means for detachablyengaging the key within the head to transmit a rotational torquethereto, a perforated sleeve screwed into the lower end of the bore inthe key so that an annular chamber with perforated wall is formedbetween the sleeve and the interior wall of the key, and a flexible hosepassing through the hollow key and communicating with the annularchamber. n

4. Pile screwing apparatus comprising in combination a screw head withva through axial bore, an axially bored screwing key, means fordetachably engaging the key within the headto transmit a `rotationalVtorque thereto, a sleeve' withscre'w threaded end portions and with anintermediate perforated portion of restricted diameter screwed into thelower end ofthe bore inthe key so that an annular chamber withperforated wal-l1 is formed between the sleeve and the interior wall ofthe key, and a flexible hose passing through the hollow key andcomlnunicating with the annular chamber. Y

5. Pile screwing apparatus comprising in combination a screw head withVa through axial bore, an axially bored screwing key, means fordetachably engaging the key within the head to transmit a' rotationaltorque thereto, va sleeve with screw threaded end portions and with aninterme'diate'perforated portion of restricted diameter screwed into thelower end of the bore in the key, an enlargement in diameter ofthe borein the key over the length thereof covered by the perforated portion ofthe sleeve, so thatan an? n ular chamber with perforated lwall is formedbetween the sleeye and said enlarged portion the boreV in the key and aflexible hose passing through the hollow key and communicating with theannular chamber. Y

6. Pile screwing apparatus comprising in combination a screw/head, atubularscrew'- ing key engaging the head, a detachable drivingconnection between the key and the head,

an orifice'd chamber nearv the lower end-ofthe bore in the key and belowthe driving connection so that the chambered portion is` kept fromtorsional stress and means for delivering air under pressureto thechamber'.r y

7. Pile screwing apparatus comprising in combinationv a screw. head witha through axial bore, an axially bored screwing key, means fordetachably engaging-the key within the head tovtransmit a 'rotationaltorque thereto, a sleeve with screw threaded end porf-` tions and with'an intermediate perforated portion of restricted diameter screwed intothe lower end of the bore in thekey and below the means for' detachablyelfig'faging the key within the head,rso` th`at the portion ofthe keycontaining. the sleeve is kept from tor?y sional stress, anenlargement'in diameter of the bore in the key over the length thereofcovered by the perforated portion of the sleeve so that an annularchamber with perforated wall is formed between the sleeve and saidenlarged portion of the bore in the key and a flexible hose passingthrough the hollow key and communicating with the annular chamber. 1

8. Pile screwing apparatus comprising in combination a screw head atubular screwing key engaging the head, a water supply pipe passingthrough the screwing key and terminating closely adjacent the lowerendthereof, an oriiiced chamber near the lower end of the bore on thekey and means for delivering air under pressure to the chamber.

9. Pile screwing apparatus comprising iny combination a screw head, witha throughy axial bore an axially bored screwing key a water supply pipepassing through the screwing key and terminating in a jet closelyadjacent the lower end thereof, means for detachably engaging the keywithin the head to transmit a rotational torque thereto, a perforatedsleeve screwed into the lower end of the bore in the key so that anannular chamber with perforated wall is formed betweenv the sleeve andthe interior wall of the key, and a flexible hose passing through thehollow key :.1 and communicating with the annular chamber.

In testimony whereof I aflix my signature.

WILLIAM ARCHIBALD RADICE.

